Jeans analysis in energy–momentum-squared gravity

Ali Kazemi; Mahmood Roshan; Ivan De Martino; Mariafelicia De Laurentis

doi:10.1140/epjc/s10052-020-7662-y

2021 Impact factor 4.991

Particles and Fields

Open Access

Eur. Phys. J. C (2020) 80: 150
https://doi.org/10.1140/epjc/s10052-020-7662-y

Regular Article - Theoretical Physics

Jeans analysis in energy–momentum-squared gravity

Ali Kazemi¹, Mahmood Roshan¹^,2^b, Ivan De Martino³^,4^,5 and Mariafelicia De Laurentis⁵^,6^,7

¹ School of Astronomy, Institute for Research in Fundamental Sciences (IPM), 19395-5531, Tehran, Iran
² Department of Physics, Faculty of Science, Ferdowsi University of Mashhad, P.O. Box 1436, Mashhad, Iran
³ Donostia International Physics Center (DIPC), 20018, Donostia-San Sebastian, Gipuzkoa, Spain
⁴ Dipartimento di Fisica, Università di Torino, Via P. Giuria 1, 10125, Turin, Italy
⁵ Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Torino, Via P. Giuria 1, 10125, Turin, Italy
⁶ Dipartimento di Fisica “E. Pancini”, Universitá di Napoli “Federico II”, Compl. Univ. di Monte S. Angelo, Edificio G, Via Cinthia, 80126, Naples, Italy
⁷ Lab. Theor. Cosmology, Tomsk State University of Control Systems and Radioelectronics (TUSUR), 634050, Tomsk, Russia

^b mroshan@um.ac.ir

Received: 5 November 2019
Accepted: 18 January 2020
Published online: 19 February 2020

Abstract

In this paper, we study the Jeans analysis in the context of energy–momentum-squared gravity (EMSG). More specifically we find the new Jeans mass for non-rotating infinite mediums as the smallest mass scale for local perturbations that can be stable against its own gravity. Furthermore, for rotating mediums, specifically for rotating thin disks in the context of EMSG, we find a new Toomre-like criterion for the local gravitational stability. Finally, the results are applied to a hyper-massive neutron star, as an astrophysical system. Using a simplified toy model we have shown that, for a positive (negative) value of the EMSG parameter , the system is stable (unstable) in a wide range of . On the other hand, no observational evidence has been reported on the existence of local fragmentation in HMNS. Naturally, this means that EMSG with positive is more acceptable from the physical point of view.

© The Author(s) 2020

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.